Have you ever noticed how mangled cars are after high-speed accidents? Although it may look chaotic, it is the result of careful design. In the 1950s, automobile engineers began incorporating crumple zones, or areas that are designed to fail in controlled and predictable ways. During a collision, the crumple zone deforms, absorbing impact energy and slowing the rate of vehicle deceleration. Understanding failure mechanisms is what allows engineers to design safer, more efficient products. My research focuses on assessing the quality of additively manufactured, or 3D printed, parts. With this new technology, we can manufacture products with fantastically complex geometries in new materials. But the question remains: how do these geometries and new materials behave under different loading conditions? To answer this, we conducted compression tests on hexagonal lattices that were printed in cyanate ester, a high-temperature-resistant polymer. As the load increased slowly (quasi-static testing), the 1 cubic inch lattice supported over 560 pounds before catastrophically failing! At 960 frames per second, we observe an extravagant explosion and release of elastic energy stored in the lattice as it fails. Next time you observe something fail, consider that perhaps it was performing exactly as intended.
